The link between ordinary sugar (sucrose) consumption and the occurrence of dental caries has been well established. As a result, a considerable amount of research has been directed toward the development of alternative sweetening systems that do not promote tooth decay. At present, the noncariogenic sweetener of choice in commercial applications is sorbitol In most cosmetic applications, such as toothpaste, technical grade liquid sorbitol is used. It contains about 70% dry solids, with at least 70% of the dry solids (50-60% of the total weight) being sorbitol. Because sorbitol at a concentration of more than 70% of the solids has a tendency to crystallize, the remaining portion of most liquid sorbitol products is a mixture of other polyols which prevent such crystallization.
Although sorbitol is, as described above, widely used, it does have some drawbacks. It has only about 60% the sweetness of sucrose. In addition, there is some evidence to suggest that frequent exposure to sorbitol may result in increased acid production in dental plaque and an increased number of sorbitol fermenting organisms within the mouth.
Reports of recent studies in which the sugar alcohol xylitol was compared to sorbitol for use as a sweetener indicate that xylitol may provide several advantages. Xylitol has been found to significantly reduce the frequency of dental caries. Thus, rather than being non-cariogenic like sorbitol, xylitol is actually cariostatic. Furthermore, xylitol's cariostatic properties are observed even when xylitol is used in conjunction with a sweetener that has cariogenic potential. In addition xylitol reduces the development of plaque. It has also been observed that xylitol reacts synergistically with fluoride. In addition, xylitol has the same sweetness as sucrose. Finally, xylitol has humectant properties that have lead to its suggested use in products such as toothpaste, where it prevents plugging of uncapped tubes. See UK Patent 1 559 989, issued to Glas and Ahlgren.
Despite suggestions in the literature that xylitol could provide valuable properties to cosmetic products, its use has been limited for several reasons. Predominantly, it has not, to date, been made available in a form that makes it shelf stable and easy to add into various formulations. Furthermore its manufacturing costs have hindered its substitution for less costly sugar alcohols.
It is therefore the object of this invention to provide a less expensive, technical grade liquid xylitol product. It is a further object of this invention to provide a liquid xylitol product which does not crystallize under normal storage conditions of concentration, time and temperature. Another object of the invention is to provide a liquid xylitol product that is as similar as possible to liquid sorbitol products, thus enabling manufacturers to readily reformulate existing products with a xylitol sweetener.